This invention relates in general to a direct-dial combination lock wherein rotation of the lock dial directly controls the location of associated tumbler means which must be placed thereby into a predetermined relationship in order to allow opening of the lock. More specifically, the present invention relates to an improvement in such direct-dial combination locks wherein the lock may not be "manipulated" by unauthorized personnel to sensing any interaction between the release lever of the lock and the associated tumbler means driven directly off rotation of the dial.
In traditional combination locks, if the dial is turned beyond any particular number in the combination, the entire sequence of numbers must be redialed. While such arrangements have been intended to make the lock more difficult to "manipulate" by unauthorized personnel, it is somewhat inconvenient to authorized personnel who may accidentally go past a number in the combination and thus has to start over again. It is therefore an object of the present invention to disclose and provide a combination lock which allows for a direct dial of a number in the combination, regardless of which may the dial is turned and regardless of whether the particular number is passed once, twice or more in indexing the number to the otherwise conventional index mark employed in combination locks.
There have been prior attempts to provide such direct-dial combination locks, as for example in the prior U.S. Pat. No. 8,593, wherein a plurality of tumbler discs were mounted for rotation relative to, and blocking movement of the bolt of the lock until gate openings in the tumbler discs were properly aligned to a portion of the bolt. And axially slidable dial means was provided in the aforenoted patent disclosure with a drive pin engaging, and sequentially releasable from each of the tumbler wheels in order to locate and successively release each in a preferred, aligned relation determined by the combination for the lock. However, it was recognized that this direct-dial lock might be "manipulated" by unauthorized personnel due to the possibility of sensing slight engagements between the gate openings of the directly dialed tumbler wheels and the portion of the bolt which the tumbler wheels were blocking until placed in the proper combination or arrangement. The attempted solution in such prior patent was to provide a plurality of false gate openings on each tumbler wheel so that a hopefully false indication of the location of the gate openings would be sensed during unauthorized manipulation of the lock. A more recent, and involved, construction of such direct-dial lock is disclosed in U.S. Pat. No. 2,104,516 employing a plurality of tumbler discs as discussed hereinbefore.
It is therefore another object of the present invention to disclose and provide a direct-dial combination lock construction which is economically constructed and simply operated employing directly dialed tumbler discs or wheels having gate openings therein but which may not be "manipulated" by unauthorized personnel through an attempted sensing of slight engagements between the tumbler wheel gate openings and a portion of the bolt or associated release lever whose movement is to be blocked by the tumbler wheels until they are properly aligned through direct dialing thereof by an associated dial means.